The material for the screws and accessories:

SK300 series, the materials are the special alloy steel for making screw which are imported from Japan and Germany.Trough 1080°C vacuum quenching and three times of 570°C tempering, four hours one time. The hardness will be HRC50-52, good function of toughness, softening resistance in high temperature, common function of anti-wear and corrosion. Alloy compsition: C:0.42, Cr:5.5,Mo:1.5,Si:1.2, W:1.0, V:1.2, Co:1.4

  Universal screw standard material, good toughness and softening resistance in high temperature make them fit for the application below 30% GF

SK400 series, the materials are the special alloy steel for making screw which are imported from Japan and Europe.Trough 1050°C vacuum quenching and three times of 520°C tempering, four hours one time. The hardness will be HRC50-52, good function of toughness, softening resistance in high temperature, common function of anti-wear and moderate function of anti corrosion. Alloy compsition: C:0.96, Cr:18.5,Mo:0.75,Si:1, W:1.2, V:0.9, Co:0.7

Good mirror finishing, fit for optics products, LGP, lens,white, PC, transparent PMMA, good function of anti corrosion.

SK500 series, the materials are the special powder alloy steel for making screw which are imported from Japan and Germany.Trough 1080°C vacuum quenching and three times of 580°C tempering, four hours one time. The hardness will be HRC55-62, common function of toughness in high temperature,good function of softening resistance in high temperature, good function of anti-wear and normal function of anti corrosion. Alloy compsition: C:1.26, Cr:4.2,Mo:5,Si:0.9, W:6.4, V:1.9, Co:2.1

Good function of anti wear which will be fit for engineering plastic+50%GF+common fire retardant and high wear environment.

SK600 series are based on SK300 alloy steel which are imported from Japan, through vacuum quenching treatment, the screw surface use the American Stellite and German Castolin Fe-based,Nickel based, cobalt-based tungsten carbide supersonic radiation technology to make the screw working part covered by alloy, depth 1-2mm, bonding strengh approximate 210bar, hardness 60-65HRC. Super function of anti wear and corrosion. Alloy composition: C:2.3, Cr:26,Mo:5.2, Si:1, W:18,Mn:1.2,Ni:0.3,V:8,Co:6

Perfect wear and corrosion resistance fit for halgo free engineering plastic+lower than 65%GF in high wear and corrosion environment.But it is very strict for production environment,working procedure and disassemble. (we do not recommend it unless special requirment.

SK700 series, the materils are halogen free spcial powder alloy for making screw which are imported from Japan and Germany. Through 1180°C vacuum quenching and 3 times of 570°C tempering, four hours one time. The hardness is 55-60HRC, perfect function of toughness and softening resistance in high termperature, super function of wear and corrosion resistance. Alloy composition: C:2.3, Cr:23, Mo:1.3, Si:1.3, W:3.2, V:8.9, Co:4.6

Perfect wear and corrosion resistance fit for halogen free engineering plastic+65%GF high temperature environment.Appliction for raw material: PPS halogen free+50%GF,PA9T halogen free+50%GF,PAT halogen free+50%GF,PA66 halogen free+65%GF, LCP halogen free, PPT halogen free+50%GF,PEEK,fluoroplastics,magnetic powder

The material for the barrels:

HK10: standard universal alloy, fit for application below 35% GF,anti medium wear and corrosion.

HK20:  fit for application below 35% GF,anti medium wear and acid corrosion  

HK30: fit for application below 50% GF, good anti  wear and corrosion  

HK50: fit for application below 50% GF, perfect anti  wear and corrosion

HK60: fit for application below 50% GF, perfect anti  wear and acid corrosion